i used to think, while repeatedly trying to quit and not making it, that i needed to understand the why of it before i could quit.
because i thought if i didn't know the underlying things/reasons why i kept drinking, then i could never have a sobriety that wasn't dependent on resolving those very things that made me...you know what i'm saying.
then it hit me that i was using the search for the ever-unknown why as an excuse to keep drinking.
later, i saw that it came down to being a drunk, and that in a very real way i drank because i am an alcoholic.
which sounded like no "reason" i could do anything with.
fact is, seeing that "irrational, non-sensical reason" was what got me to quit.
couple of other thoughts: reason for is NOT the same as cause of.
and the one time i went to therapy for a few sessions, i rather tiredly asked the therapist right at the outset if she thought it was necessary to find the reasons, causes or why of the behaviour i wanted to stop suffering with, and she said no, in fact you can change behaviour without needing to know the reasons why you developed it.
trust that it was a "solution" of sorts to whatever was going on in the past, and yes, you can change your responses without the understanding. it will work just as well and save lots of money and time.
chances are, you can't do anything about whatever "started" it anyway.
for me, though, i've come to the place where i can just say and do believe the "shrug; i'm an alcoholic". that is the cause.
what causes alcoholism....i don't know and no-one else does, exactly, either. or even what it is, exactly.
i don't have the burning need to understand it anymore.
what i had to do was see it and accept it and go from there.